> My understanding is that when CONCURRENTLY is specified, Postgres implements the refresh as a series of INSERT, UPDATE, > and DELETE statements on the existing view. So the answer to your question is no, Postgres doesn’t create another table and > then swap it. The INSERTS/UPDATE/DELETE happens only for the difference. PG first creates a new temp table and then compares it with the MV and detects the difference. That is why for CONCURRENTLY, a unique index is required on the MV.
